This is an interactive visualisation (35MB heavy, takes some time loading) of the Gaia DR2 Radial Velocity sample selection function. In the top left panel you see a CMD showing the overall RVS sample starcounts per color magnitude bin. Binning is done 0.2 mag in G_RVS magnitude and 0.1 mag in G-G_RP color. In the top right and the bottom panel you see sky-maps (Mollweide projection, Galactic coordinates with Galactic center in the middle and longitude increasing to the left in HEALpix level 4). In the bottom panel you see the completeness (starcounts in GDR2_RVS divided by GDR2_all) and on the top right the HEALpix level over which was averaged in order to get at least 5 GDR2_all sources in the respective CMD bin. Grey pixels have no starcounts at all. The native resolution is HEALpix level 6, we only display level 4 here for memory reasons. You can hover over the CMD or click on the respective CMD bin in order to keep the depiction on the skymaps fixed (this usually needs several clicks). You can also automatically go through the magnitude and color bins using the 'Play' button. The button below determines through which variable you want to scroll first.
This visualisation has been mainly created by William Cooper (University of Hertfordshire). The data and selection function can be accessed in a python function via gdr2_completeness package. The reference paper is on arxiv.